1. Field of the Invention
This invention relates to an auxiliary bed device for a free arm type overlock machine.
2. Prior Art
Overlock machines form overlock stitches by cooperative operations of a vertically movable needle holding a needle thread, an upper looper holding an upper looper thread passed through a thread hole at the tip end portion thereof operating across a workpiece feed direction and a lower looper holding a lower looper thread. A free arm type overlock machine, in general, has a free arm and an auxiliary bed (auxiliary table), thereby only the free arm being used to sew cylindrical workpieces, such as cuffs and bottom edges of pants legs, and pouches, while the auxiliary bed being used, in combination with the free arm, to sew ordinary flat workpieces. The free arm type overlock machine is well adapted to sew cylindrical workpieces and pouches, however, because of a narrow holding area thereof, it should be necessary to attach the auxiliary bed to sew ordinary flat ones so as to widen the holding area.
Thus, in a case of such a conventional free arm type overlock machine in which the auxiliary bed is attached and detached depending on a kind of workpieces, although it has been known to allow the auxiliary bed to be detachable to the free arm to increase the durability and reliability, an attaching or detaching operation of the auxiliary bed is required every when the kind of workpieces is changed, which is considerably troublesome.